Reversible rotary fan



A. P. ALLEN REVERSIBLE ROTARY FAN Filed July 5, 1951 FIG Juventor ARTHUR P. ALLEN Patented Dec. 2, 1952 UNITED STATES PATENT OFFICE REVERSIBLE ROTARY FAN Arthur P. Allen, Spokane, Wash.

Application July 3, 1951, Serial No. 235,027

1 Claim. 1

This invention relates to improvements in fans, and more particularly to means for adjusting the angle of the blades of the fan to direct the air currents therefrom in one direction or the other. The invention is primarily intended for use on slow moving and stationary equipment of the type powered by an internal combustion engine which includes a radiator core and fan to facilitate maintaining the engine at proper operating temperature.

One object of the invention lies in the provision of a multi-bladed rotary fan adapted for use with an internal combustion engine and which has blade angle adjusting mean-s in the form of a Wedge-shaped block for each blade.

Another object of the invention lies in the provision of a multi-bladed rotary fan with a securing collar having radially extending arms to which the blades are secured.

Another object of the invention lies in the pro- 3 vision of a lip and a tongue on each of the Wedgeshaped blocks to resist torsional strain between the fan blades and arms, and to prevent relative movement therebetween.

Another object of the invention lies in the provision of bolts and nuts for releasably securing the angled blades so that the angle may be reversed with ease, the bolts having angled heads to conform to the angle of the blades.

Other objects and advantages will become apparent during the course of the following description:

In the accompanying drawings, forming a part of this application, and in which like numerals are used to indicate like parts,

Figure 1 is a perspective view of my improved fan,

Figure 2 is a view in perspective and upon an enlarged scale showing one of the wedge-shaped blocks which I utilize to adjust the angle of the blades, and, Figure 3 is a plan view of one blade mounted on an arm with a block disposed therebetween and with the blade shown in the reversed position by dotted lines.

In the exemplifying drawings, I have shown one physical embodiment of my invention. which may be manufactured with facility and is adapted for use on equipment of the type described such as crawler type tractors, stationary diesel-generators and the like.

To mount my improved fan, I provide it with a collar 4 having multiple bolt holes 5 circumferentially spaced about the collar and extending axially through said collar from the front side face 6, for mounting the fan on the driven hub of an engine. The number and circumferential spacing of the bolt holes 5 are such as to adapt the fan for mounting upon the equipment of one manufacturer, but it will be understood that various combinations of positioned holes may be used to adapt the fan for mounting upon any existing piece of equipment.

The collar 4 has a central opening or aperture 1 to allow for the protruding bearing present on some makes of machines and radially extending spaced arms 8 are formed integral with said collar. The arms shown are six in number but it will be understood that collars having various numbers of arms will be equally as effective for the purpose.

Each arm 8 is provided with a transverse groove 9 extending across the rear side face thereof and substantially midway the length of the arm. The slots are arranged so that they are equidistant from the collar 4 and thus arranged in a concentric circle spaced from the collar.

To mount fan blades l0 upon their respective arms, I provide a wedge-shaped block II which has an angular rear face 12 and a flat front face l3. A tongue It extends transversely across the front face l3 midway its length and impinges against a longitudinally extending lip l5 which extends the full length of the block ll adjacent one edge thereof. The lip I5 is of greater height than the tongue l4 and therefore its upper face I5 is slightly spaced above the upper face 14 of tongue I4. The wedge shaped block II is thus formed with a wide side edge and tapers to a narrow opposed side edge.

Spaced bolt holes I6 are drilled through each block II at right angles to the flat front face 13, and when the block II is mounted on its respective arms, in face to face relation, the tongue l4 cooperates with the groove 9 of the arm and the lip I5 depends over one edge, thus securely fastening the block ll against torsional movement.

Holes iii in the blocks H are drilled to be aligned with bolt holes I! in each arm, and bolts [8 are passed through aligned holes in one end of blades l0 and through holes l6 and I1 and thence secured as by nuts I9. The bolts l8 are provided with angled heads 20 which conform to the angle of the blades Ill when secured upon blocks l I.

To reverse the blades H] from the full line position of Fig. 2 to the dotted line position, it is necessary to remove bolts and nuts 18 and 119, turn blocks I 1 end for end, which will dispose the wide side edge in the opposite direction, and replace the blade with the opposite side face in face to face relation with the angled side face [2 of block I I The bolts may then be inserted through the aligned holes in the blades, blocks and arms and nuts l9 applied to secure the blades. This reversing of the blades, causes the fan to force the air in the opposite direction, thus making a blower fan out of a suction fan.

In Figure 3 the arrow R. indicates the direction of rotation and the arrow F indicates the travel of air being forced by the fan when in the full line position. The dotted arrow D indicates the air travel with the blades in the reversed or dotted position.

Having thus described my invention, I desire to secure by Letters Patent and claim:

A reversible pitch rotary fan comprising a collar adapted to be secured to a rotatable hub, radially extending arms on the collar and integral therewith, a groove in each arm extending transversely thereof and positioned substantially midway the length thereof on their rear side faces, bolt receiving holes through said arms and spaced from each other longitudinally thereof, a reversible wedge-shaped block on each arm, bolt receiving holes in each block aligned with said first mentioned bolt receiving holes, a transversely extending tongue on said block cooperating with said groove, reversible pitch blades having holes in one end aligned with said bolt receiving holes and mounted upon said blocks, and bolts having angled heads and passing through said holes and secured by nuts.

ARTHUR P. ALLEN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 587,245 Stellner July 27, 1897 671,527 Phillips Apr. 9, 1901 

